Microcirculatory Responses to Hyperoxia in Macular and Peripapillary Regions

To evaluate the hyperoxia response of the retinal vascular system in different parts of the fundus using optical coherence tomography (OCT) angiography.

Using an OCT angiography system and a split-spectrum amplitude decorrelation angiography (SSADA) algorithm, perfused vessel density at the macular and peripapillary regions was measured before and after breathing 80% oxygen in 10 healthy Chinese subjects. The repeatability of the hyperoxia response was also tested.

Hyperoxia provocation caused a significant decrease in retinal perfused vessel density in both the macular and peripapillary areas. The para- and perifoveal area had a mean reduction of 13.66% and 15.17%, respectively; these reductions were significantly greater than in the peripapillary area (9.52%; parafovea versus peripapillary, P = 0.023; perifovea versus peripapillary, P = 0.006). The coefficients of variation (CV), intraclass correlations (ICC), and Bland-Altman plots suggested strong repeatability of the hyperoxia response.

The optical coherence tomography system, in conjunction with the SSADA algorithm, recorded a significant reduction in retinal perfused vessel density after hyperoxia, and the reduction was greater in the macular area than in the peripapillary area.